On Fri, 27 Mar 2020 09:41:55 +0000 "Tian, Kevin" <kevin.t...@intel.com> wrote:
> > From: Jacob Pan <jacob.jun....@linux.intel.com> > > Sent: Thursday, March 26, 2020 1:55 AM > > > > Bare metal SVA allocates IOASIDs for native process addresses. This > > should be separated from VM allocated IOASIDs thus under its own > > set. > > A curious question. Now bare metal SVA uses the system set and guest > SVA uses dynamically-created set. Then do we still allow ioasid_alloc > with a NULL set pointer? > Good point! There shouldn't be NULL set. That was one of the sticky point in the previous allocation API. I will add a check in ioasid_alloc_set(). However, there is still need for global search, e.g. PRS. https://lore.kernel.org/linux-arm-kernel/1d62b2e1-fe8c-066d-34e0-f7929f6a7...@arm.com/#t In that case, use INVALID_IOASID_SET to indicate the search is global. e.g. ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL); > > > > This patch creates a system IOASID set with its quota set to > > PID_MAX. This is a reasonable default in that SVM capable devices > > can only bind to limited user processes. > > > > Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com> > > --- > > drivers/iommu/intel-iommu.c | 8 +++++++- > > drivers/iommu/ioasid.c | 9 +++++++++ > > include/linux/ioasid.h | 9 +++++++++ > > 3 files changed, 25 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/intel-iommu.c > > b/drivers/iommu/intel-iommu.c index ec3fc121744a..af7a1ef7b31e > > 100644 --- a/drivers/iommu/intel-iommu.c > > +++ b/drivers/iommu/intel-iommu.c > > @@ -3511,8 +3511,14 @@ static int __init init_dmars(void) > > goto free_iommu; > > > > /* PASID is needed for scalable mode irrespective to SVM */ > > - if (intel_iommu_sm) > > + if (intel_iommu_sm) { > > ioasid_install_capacity(intel_pasid_max_id); > > + /* We should not run out of IOASIDs at boot */ > > + if (ioasid_alloc_system_set(PID_MAX_DEFAULT)) { > > + pr_err("Failed to enable host PASID > > allocator\n"); > > + intel_iommu_sm = 0; > > + } > > + } > > > > /* > > * for each drhd > > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c > > index 6265d2dbbced..9135af171a7c 100644 > > --- a/drivers/iommu/ioasid.c > > +++ b/drivers/iommu/ioasid.c > > @@ -39,6 +39,9 @@ struct ioasid_data { > > static ioasid_t ioasid_capacity; > > static ioasid_t ioasid_capacity_avail; > > > > +int system_ioasid_sid; > > +static DECLARE_IOASID_SET(system_ioasid); > > + > > /* System capacity can only be set once */ > > void ioasid_install_capacity(ioasid_t total) > > { > > @@ -51,6 +54,12 @@ void ioasid_install_capacity(ioasid_t total) > > } > > EXPORT_SYMBOL_GPL(ioasid_install_capacity); > > > > +int ioasid_alloc_system_set(int quota) > > +{ > > + return ioasid_alloc_set(&system_ioasid, quota, > > &system_ioasid_sid); +} > > +EXPORT_SYMBOL_GPL(ioasid_alloc_system_set); > > + > > /* > > * struct ioasid_allocator_data - Internal data structure to hold > > information > > * about an allocator. There are two types of allocators: > > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h > > index 8c82d2625671..097b1cc043a3 100644 > > --- a/include/linux/ioasid.h > > +++ b/include/linux/ioasid.h > > @@ -29,6 +29,9 @@ struct ioasid_allocator_ops { > > void *pdata; > > }; > > > > +/* Shared IOASID set for reserved for host system use */ > > +extern int system_ioasid_sid; > > + > > #define DECLARE_IOASID_SET(name) struct ioasid_set name = { 0 } > > > > #if IS_ENABLED(CONFIG_IOASID) > > @@ -41,6 +44,7 @@ int ioasid_register_allocator(struct > > ioasid_allocator_ops *allocator); > > void ioasid_unregister_allocator(struct ioasid_allocator_ops > > *allocator); int ioasid_attach_data(ioasid_t ioasid, void *data); > > void ioasid_install_capacity(ioasid_t total); > > +int ioasid_alloc_system_set(int quota); > > int ioasid_alloc_set(struct ioasid_set *token, ioasid_t quota, int > > *sid); void ioasid_free_set(int sid, bool destroy_set); > > int ioasid_find_sid(ioasid_t ioasid); > > @@ -88,5 +92,10 @@ static inline void > > ioasid_install_capacity(ioasid_t total) { > > } > > > > +static inline int ioasid_alloc_system_set(int quota) > > +{ > > + return -ENOTSUPP; > > +} > > + > > #endif /* CONFIG_IOASID */ > > #endif /* __LINUX_IOASID_H */ > > -- > > 2.7.4 > [Jacob Pan] _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu